Yep, if you go to the front end, and hover over the arrow in each of the stream item, you will be able to delete them if you want / need to

I am feeling so stupid now .
Didn't think that i am the admin and maybe i can delete the items from frontend ))))))
I have the "joomla" syndrome, where i expect all the admin task in backend. I didn't even think about frontend when i say "admin stuff"

Thanks for the hint !

I was thinking now that maybe a cron or some kind of a mantainance task should be implemented to prune the activities items older than X days/months ...

Hello,

Hm, not sure if this makes sense because on a less active site, their stream would be pretty much empty

I agree with Dr D on this. I actually thought about this many months ago but figured I'd save the request for later. While famous sites keep all activity data, some of us might want to reduce our server impact after getting our communities big. I'm not saying I would want an auto purge after just 30 days which indeed would feel limited for the users. But perhaps a year or two, maybe even 3-4 years of time might be a good cut off time to have the data auto purge. It's not just to save space, but posts aren't as relevant and are much less visible due to being buried so deep. Their articles and such would still display in the profile themselves.

Even more important is auto purging of old private messages. The admin should be able to specify the time length for both of these. There is a free Joomla extension that has this capability.

Noted, will keep an eye on this